Page Length Measurement - Epson LX-300+ Service Manual

LX-300+/1170
RPE DETECTOR
RPE detector is installed on the paper path at the back of the printer. The table below shows
the RPE detector specifications.
Table 2-11. RPE Detector Specifications
Item
Method
Switching rate
Switching mode
BPE DETECTOR
BPE detector is installed right under the platen. The table below shows the BPE detector
specifications.
Table 2-12. BPE Detector Specifications
Item
Method
Switching rate
Switching mode
Operating Principles
Specification
Mechanical contact method
0.6 to 1.0 mA, 5 VD±5%
• Paper inside: open
• No paper: close
Specification
Mechanical contact method
0.6 to 1.0 mA, 5 VD±5%
• Paper inside: open
• No paper: close

2.2.5.1 Page Length Measurement

Page length measurement is a process to convert the following value to the number of
printing lines.
Value = [The number of paper feed pulse from the paper top (top margin: 4.2mm) until RPE
detector detects paper end] + [forms over-ride specified paper feed pulse] - [adjustment
value]
o
When CSF is used:
The uncertainty of the paper end detector may vary the number of printing lines
within the same paper size. To avoid this, when CSF is used, page length
measurement calculates the printable lines and if the paper is longer than the
printable lines, the number of printing line is considered the printable lines (fixed
value).
When paper is shorter than the printable lines, the printer prints the fixed number
of lines by forms over-ride function (which allows the fixed number of lines to be
printed even when RPE detector detects paper end).
o
When CSF is not used:
When loading paper manually or when tractor feed is used, the number of printing
lines of paper end is determined by forms over-ride function after BPE or RPE
detector detects paper end.
Printer Mechanism
Revision C
54